Throttle Body Polish/Port Matching

charleswrivers

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Has anyone seen how out throttle bodies look or how they're matched up to the manifold? Just curious. I didn't know if it was rough/had casting lines that had room for improvement.

I'm not looking to try and go larger and lose velocity... just didn't know if anyone has taken a look at them. In my Z31 days, 60mm 240sx TB swaps were common... which our stock guys being something like 54mm... with port matching to bring it all together. I hadn't seen a thread about it specificially, though businesses are selling us silicone intake hoses... working on new intake ducting to replace the pancake shaped plastic guy and so on. What about the part that was made to actually restrict airflow? Anyone fool around with this at all on our 10th gens?
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The factory throttle is small, but so is an RSX throttle, and I've moved 800whp worth of air through one of those with ease, so I don't think you're going to see much gain with a larger throttle on one of these engines with the stock turbo on it.

The turbo is honestly the restriction.
 
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charleswrivers

charleswrivers

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The factory throttle is small, but so is an RSX throttle, and I've moved 800whp worth of air through one of those with ease, so I don't think you're going to see much gain with a larger throttle on one of these engines with the stock turbo on it.

The turbo is honestly the restriction.
I figured as much... and also figured we'd be giving up air velocity and the ability for fine throttle control over a bigger TB. I didn't know if it's worth working on it a little at the inner edge for a smoother transition and make it a little more... well... nozzle-y... kind of like what a velocity stack does. Had a spare off the Z...
Honda Civic 10th gen Throttle Body Polish/Port Matching IMG_20190311_173620070

I don't know how much material there is or if there's a lip in the transition between in intake hoses that connects to the TB... just thought of taking the lip off it and polishing it if it could use it.


I looked at it today when I was changing my MTF. Uuuugh... it looks like it's kind of in a PITA spot to get to if I followed it right... just behind the top of the block sport of on the driver's side near the heater core coolant lines.
 

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Has anyone seen how out throttle bodies look or how they're matched up to the manifold? Just curious. I didn't know if it was rough/had casting lines that had room for improvement.

I'm not looking to try and go larger and lose velocity... just didn't know if anyone has taken a look at them. In my Z31 days, 60mm 240sx TB swaps were common... which our stock guys being something like 54mm... with port matching to bring it all together. I hadn't seen a thread about it specificially, though businesses are selling us silicone intake hoses... working on new intake ducting to replace the pancake shaped plastic guy and so on. What about the part that was made to actually restrict airflow? Anyone fool around with this at all on our 10th gens?
I did have my 2015 1.5ltr Honda Fit throttle body bored out. Posted a lot of information about it on the FitFreak Forums --> Maxbore Throttle Body
All my pics have been lost though. The opening size difference was measurable as well as the weight difference from the metal removed (All information in the thread). At the track, I did not measure any difference in 1/4 mile time or trap speeds with the modification though. My maf g/s did go up slightly. I measured no more hp/tq in my Torque Pro app though.

As for the intake manifold piece that was made to restrict airflow on our platform, someone did have a thread where they took a picture of before and after removing this piece. If I remember correctly, they measured a noticeable increase in their maf g/s numbers. There was something else that was off (Not right) after this was done but it was something very minor. I'm looking for that post now. My car is currently in the shop. I was just looking at the intact manifold earlier today with the throttle body attached to it. That piece inside the manifold that 'straightens' out the air I am having it removed (Just asked my mechanic if he'd remove it earlier). It'll be a straight through hole rather than having that piece blocking/restricting the air off. Only doing it because I remember that old post and there was no negative effects of removing it. Perhaps it was some more fuel usage. Looking for that post/thread now.
 

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Ah, the post was for the 2.0ltr Intake Manifold. ---> HERE

That intake manifold part you are talking about (I think) is the pic I've posted below.

Honda Civic 10th gen Throttle Body Polish/Port Matching Manifold.JPG
 


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Myx

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@charleswrivers

I may as well post what the @DarkLight said in the 2.0ltr thread here. In case that thread gets deleted, lost, etc.

Lately, I ditched my K24 manifold in favor of the stock unit, albeit modified.

What I did was remove the cutout that is located directly behind the throttle plate. I also radiused the outlets of the individual runners (not pictured).

IMG_0103.JPG


IMG_0105.JPG


This is designed to reduce turbulence caused by the throttle plate at part throttle, which increases fuel economy and smoothness under normal driving conditions. However, it does pose a restriction at wide open throttle, and removing it resulted in sizeable gains across the rev range, but most noticeably beyond 5.5K RPM's.

My injector duty cycle increased by 6% (from 74 to over 80% at peak) over the non-ported setup. My short term fuel trims increased as well.

IMG_0104.JPG


In addition, I have also had MAP readings, particularly low in the rev range, where pressure was beyond atmospheric, suggesting that intake efficiency beyond 100% was achieved at certain engine speeds.

All in all, the car feels stronger everywhere, but especially at the top end. Noticeable power was also gained below 2.5K RPM's.
 
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charleswrivers

charleswrivers

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Honda Civic 10th gen Throttle Body Polish/Port Matching EA471379-50DC-4AFA-8AFD-7DD517544B3B

Pic isn’t mine... it’s just one I found.

Ever half shaft/grind down a throttle body shaft? I saw the picture and throughly of how wide the shaft was.

Check out pages 355/356.
http://nopr.niscair.res.in/bitstream/123456789/23129/1/IJEMS 20(5) 350-360.pdf

They give a 3 g/s increase in flow at WOT for a small engine that had drew 42 g/s at WOT. I bummed around the internet and I guess it’s been done here and there on a lot of cars. Very minimal objective data to show whether it’s does anything or not. Not sure it’s anything I’d ever do and may do nothing on a tiny-turbo limited car. I can see it being a no brainer on an NA.
 
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EA471379-50DC-4AFA-8AFD-7DD517544B3B.png

Pic isn’t mine... it’s just one I found.

Ever half shaft/grind down a throttle body shaft? I saw the picture and throughly of how wide the shaft was.

Check out pages 355/356.
http://nopr.niscair.res.in/bitstream/123456789/23129/1/IJEMS 20(5) 350-360.pdf

They give a 3 g/s increase in flow at WOT for a small engine that had drew 42 g/s at WOT. I bummed around the internet and I guess it’s been done here and there on a lot of cars. Very minimal objective data to show whether it’s does anything or not. Not sure it’s anything I’d ever do and may do nothing on a tiny-turbo limited car. I can see it being a no brainer on an NA.
So in essence, it increased airflow by 7% if I'm right (3/42). Sounds significant enough for something I'd do. Definitely would've done it on my N/A Honda Fit but it's the little things I am big on. I've never even heard of this being done. Thanks for sharing! Getting my popcorn and getting ready to dig into the .pdf file. Woot Woot!
 
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charleswrivers

charleswrivers

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So in essence, it increased airflow by 7% if I'm right (3/42). Sounds significant enough for something I'd do. Definitely would've done it on my N/A Honda Fit but it's the little things I am big on. I've never even heard of this being done. Thanks for sharing! Getting my popcorn and getting ready to dig into the .pdf file. Woot Woot!
There’s actually a handful of PDFs floating around the internet from folks... I assume mostly doing capstone projects and such for college. There’s quite a few instances of it all over Internet forums... but none I’d ever frequented. Most of them have zero data to back them. There was some mentions of gains on some Mustang forums.., but couldn’t ever find before/after dynos.

I don’t know... just figured I’d share what I saw. I thought it was kind of intriguing... even though seeing how horsepower plateaus on the small stock-turbo’ed cars with a little extra boost... I doubt it’d help much at all at WOT. Might be able to get a spare out of a junker. I thought there was a data log parameter for total airflow... so it would be something that could be quantified... and you’d just have to temperature correct for air density to rule out an ambient temp change as causing an improvement... which I think was 1.1% per 10F if memory serves. I’d have to look it back up.
 
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There’s actually a handful of PDFs floating around the internet from folks... I assume mostly doing capstone projects and such for college. There’s quite a few instances of it all over Internet forums... but none I’d ever frequented. Most of them have zero data to back them. There was some mentions of gains on some Mustang forums.., but couldn’t ever find before/after dynos.

I don’t know... just figured I’d share what I saw. I thought it was kind of intriguing... even though seeing how horsepower plateaus on the small stock-turbo’ed cars with a little extra boost... I doubt it’d help much at all at WOT. Might be able to get a spare out of a junker. I thought there was a data log parameter for total airflow... so it would be something that could be quantified... and you’d just have to temperature correct for air density to rule out an ambient temp change as causing an improvement... which I think was 1.1% per 10F if memory serves. I’d have to look it back up.
It's very interesting stuff. I'd do it.
Throttle body shaft modification
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